Elicitation of Neutralizing Antibody Responses to HIV-1 Immunization with Nanoparticle Vaccine Platforms

Ferritin and Encapsulin Nanoparticles as Effective Vaccine Delivery Systems: Boosting the Immunogenicity of the African Swine Fever Virus C129R Protein

Vaccination remains the most effective strategy for preventing infectious diseases. Subunit vaccines, which consist of antigenic components derived from pathogens, offer significant advantages in terms of biosafety, ease of preparation, and scalability. However, subunit vaccines often exhibit lower immunogenicity than whole-pathogen vaccines do. To address this limitation, coupling antigens with nanoparticles has emerged as a promising strategy for enhancing immune responses by mimicking pathogen structures and improving antigen presentation. This study evaluated the stability of ferritin (F-nps) and encapsulin (E-nps) nanoparticles and their efficient uptake by bone-marrow-derived dendritic cells (BMDCs) in vitro. In vivo studies demonstrated their effective targeting of lymph nodes. The African swine fever virus C129R protein was conjugated to ferritin and encapsulin nanoparticles to assess its ability to enhance antigen-specific immune responses. In murine models, both F-nps and E-nps significantly increased the immunogenicity of the C129R antigen, highlighting their potential as effective vaccine delivery systems. These findings underscore the promise of ferritin and encapsulin nanoparticles as delivery platforms for enhancing antigen immunogenicity and pave the way for the development of nanoparticle-based vaccines.

Advances in engineered nanosystems: immunomodulatory interactions for therapeutic applications

Advances in nanotechnology have led to significant progress in the design and fabrication of nanoparticles (NPs) with improved therapeutic properties. NPs have been explored for modulating the immune system, serving as carriers for drug delivery or vaccine adjuvants, or acting as therapeutics themselves against a wide range of deadly diseases. The combination of NPs with immune system-targeting moieties has facilitated the development of improved targeted immune therapies. Targeted delivery of therapeutic agents using NPs specifically to the disease-affected cells, distinguishing them from other host cells, offers the major advantage of concentrating the therapeutic effect and reducing systemic side effects. Furthermore, the properties of NPs, including size, shape, surface charge, and surface modifications, influence their interactions with the targeted biological components. This review aims to provide insights into these diverse emerging and innovative approaches that are being developed and utilized for modulating the immune system using NPs. We reviewed various types of NPs composed of different materials and their specific application for modulating the immune system. Furthermore, we focused on the mechanistic effects of these therapeutic NPs on primary immune components, including T cells, B cells, macrophages, dendritic cells, and complement systems. Additionally, a recent overview of clinically approved immunomodulatory nanomedicines and potential future perspectives, offering new paradigms of this field, is also highlighted.

A ferritin-based nanoparticle displaying a neutralizing epitope for foot-and-mouth disease virus (FMDV) confers partial protection in guinea pigs

BACKGROUND

Foot-and-mouth disease (FMD) is a devastating disease affecting cloven-hoofed animals, that leads to significant economic losses in affected countries and regions. Currently, there is an evident inclination towards the utilization of nanoparticles as powerful platforms for innovative vaccine development. Therefore, this study developed a ferritin-based nanoparticle (FNP) vaccine that displays a neutralizing epitope of foot-and-mouth disease virus (FMDV) VP1 (aa 140-158) on the surface of FNP, and evaluated the immunogenicity and protective efficacy of these FNPs in mouse and guinea pig models to provide a strategy for developing potential FMD vaccines.

RESULTS

This study expressed the recombinant proteins Hpf, HPF-NE and HPF-T34E via an E. coli expression system. The results showed that the recombinant proteins Hpf, Hpf-NE and Hpf-T34E could be effectively assembled into nanoparticles. Subsequently, we evaluated the immunogenicity of the Hpf, Hpf-NE and Hpf-T34E proteins in mice, as well as the immunogenicity and protectiveness of the Hpf-T34E protein in guinea pigs. The results of the mouse experiment showed that the immune efficacy in the Hpf-T34E group was greater than the Hpf-NE group. The results from guinea pigs immunized with Hpf-T34E showed that the immune efficacy was largely consistent with the immunogenicity of the FMD inactivated vaccine (IV) and could confer partial protection against FMDV challenge in guinea pigs.

CONCLUSIONS

The Hpf-T34E nanoparticles stand out as a superior choice for a subunit vaccine candidate against FMD, offering effective protection in FMDV-infected model animals. FNP-based vaccines exhibit excellent safety and immunogenicity, thus representing a promising strategy for the continued development of highly efficient and safe FMD vaccines.

Rethinking the application of nanoparticles in women's reproductive health and assisted reproduction

Nanoparticles and nanotechnology may present opportunities to revolutionize the prevention, treatment and diagnosis of a range of reproductive health conditions in women. These technologies are also used to improve outcomes of assisted reproductive technology. We highlight a range of these potential clinical uses of nanoparticles for polycystic ovary syndrome, endometriosis, uterine fibroids and sexually transmitted infections, considering in vitro and in vivo studies along with clinical trials. In addition, we discuss applications of nanoparticles in assisted reproductive technology, including sperm loading, gamete and embryo preservation and preventing preterm birth. Finally, we present some of the concerns associated with the medical use of nanoparticles, identifying routes for further exploration before nanoparticles can be applied to women's reproductive health in the clinic.

Development of LIBRA-seq for the guinea pig model system as a tool for the evaluation of antibody responses to multivalent HIV-1 vaccines

Consistent elicitation of serum antibody responses that neutralize diverse clades of HIV-1 remains a primary goal of HIV-1 vaccine research. Prior work has defined key features of soluble HIV-1 Envelope (Env) immunogen cocktails that influence the neutralization breadth and potency of multivalent vaccine-elicited antibody responses including the number of Env strains in the regimen. We designed immunization groups that consisted of different numbers of SOSIP Env strains to be used in a cocktail immunization strategy: the smallest cocktail (group 2) consisted of a set of two Env strains, which were a subset of the three Env strains that made up group 3, which, in turn, were a subset of the six Env strains that made up group 4. Serum neutralizing titers were modestly broader in guinea pigs that were immunized with a cocktail of three Envs compared to cocktails of two and six, suggesting that multivalent Env immunization could provide a benefit but may be detrimental when the cocktail size is too large. We then adapted the LIBRA-seq platform for antibody discovery to be compatible with guinea pigs, and isolated several tier 2 neutralizing monoclonal antibodies. Three antibodies isolated from two separate guinea pigs were similar in their gene usage and CDR3s, establishing evidence for a guinea pig public clonotype elicited through vaccination. Taken together, this work investigated multivalent HIV-1 Env immunization strategies and provides a novel methodology for screening guinea pig B cell receptor antigen specificity at a high-throughput level using LIBRA-seq.IMPORTANCEMultivalent vaccination with soluble Env immunogens is at the forefront of HIV-1 vaccination strategies but little is known about the influence of the number of Env strains included in vaccine cocktails. Our results suggest that adding more strains is sometimes beneficial but may be detrimental when the number of strains is too high. In addition, we adapted the LIBRA-seq platform to be compatible with guinea pig samples and isolated several tier 2 neutralizing monoclonal antibodies, some of which share V and J gene usage and >70% CDR3 identity, thus establishing the existence of public clonotypes in guinea pigs elicited through vaccination.

Protein-based Nanoparticle Vaccine Approaches Against Infectious Diseases

The field of vaccine development has seen an increase in the number of rationally designed technologies that increase effectiveness against vaccine-resistant pathogens, while not compromising safety. Yet, there is still an urgent need to expand and further understand these platforms against complex pathogens that often evade protective responses. Nanoscale platforms have been at the center of new studies, especially in the wake of the coronavirus disease 2019 (COVID-19), with the aim of deploying safe and effective vaccines in a short time period. The intrinsic properties of protein-based nanoparticles, such as biocompatibility, flexible physicochemical characteristics, and variety have made them an attractive platform against different infectious disease agents. In the past decade, several studies have tested both lumazine synthase-, ferritin-, and albumin-based nanoplatforms against a wide range of complex pathogens in pre-clinical studies. Owed to their success in pre-clinical studies, several studies are undergoing human clinical trials or are near an initial phase. In this review we highlight the different protein-based platforms, mechanisms of synthesis, and effectiveness of these over the past decade. In addition, some challenges, and future directions to increase their effectiveness are also highlighted. Taken together, protein-based nanoscaffolds have proven to be an effective means to design rationally designed vaccines, especially against complex pathogens and emerging infectious diseases.